@FreekStar
I am not going to send the bride a pic! If I was the bride and some random guest I don't really know sent me their outfit for approval I'd think they were nuts! Do people really do this in real life?
No, they don't
I am so very pleased to have never attended a wedding in the UK. The rules and do's and don'ts are quite mad.
At my brothers wedding, his bil turned up in shorts and tshirt and flops, and his sil in leggings and a not very flattering top. Actually now I think about it, it was white as well. We just assumed they got the dress code wrong, it was near a beach but not on the beach. And then we all just carried on enjoying the wedding and that was that. There was none of what some posters upthread have claimed might happen should OP wear (imo) a very suitable dress for a guest.
For us, a wedding day is about the couple and their marriage. It is not about who is trying to outdo who in outfits.